Electrocatalysis of the oxygen reduction process on metal chelates in acid electrolyte

The electrochemical performances of carbon gas—diffusion oxygen electrodes in acid solution were investigated. Active carbon AG-3 was promoted with 5 – 10 wt.% organic complexes of cobalt (phthalocyanine, tetraphenylporphin, tetrabenzoporphin, tetra(p-metoxyphenyl)porphin); Teflon was used as binder. It was shown that a heat treatment of the mixture of carbon with the organic complexes of cobalt in an inert gas atmosphere at 800 – 900 °C significantly improves the stability of the catalyst. Oxygen electrodes with this catalyst operated in sulphuric acid solution for several thousand hours without any deterioration.